which igbt module to use for speed control

dear friends
i'm making a 440 volt A.C, 2 HP, 3 phase, induction motor speed controller using PWM. i have to use IGBT's (6 of them, as for 3 phase). which one would you guys suggesst to me .
thank you

You say 440V, the chances are you will get a nice big turn-off overshoot. 600V die is alread a bit close. That leaves 1200V die

2HP - at what speed? That will govern the current rating of the IGBT's

Personally I like Eupec IGBT bricks, have a look at their website. one thing STAY AWAY FROM SEMILAB!!!!! And I am deadly searious on this one

thanks friend for replying.the speed at which my motor will run is 960 rpm.
tell me the best igbt suited for this application and its current rating.

not much to ask...

Well 2hp = 1491.3W

Thus the mechanical power ~ 1500W

P = Tw

you say 960rpm ~ 100 rads

Thus the Torque is = 15Nm


Now the thing about sizing The IGBT's I have already mentioned 1200V devices (due to your link voltage). However, the current rating will be dependant on the load

I have said that the output torque ~15Nm, Torque = i*kt Without any infomation about the torque constant of the machine the current handling of the IGBT's cannot be stated. If the toruqe constant is low the you could need 1000A, but it if is high you could need 10A

Specing and inverter is not easy esp with no infomation,

DIY is fine, i do it all the time but here is just one little thing to
think about:
the IGBTs are in my experience quite expencive. as far as I know,
this should set you back for some $150-200 not to mention
other costs and developing.
if you are building just one unit, blowing module could be major
setback considering that complete 2HP industrial VFD can be
purchased for as little as $230-260 (or maybe even cheaper?).

Styx said:

not much to ask...
I have said that the output torque ~15Nm, Torque = i*kt Without any infomation about the torque constant of the machine the current handling of the IGBT's cannot be stated. If the toruqe constant is low the you could need 1000A, but it if is high you could need 10A

Click to expand...

1000A :shock: unlikely - normal sort of figures for torque constant of this size motor seems to be about 1.0 Nm/A (give or take a bit). Thus the current rating of the IGBTs should probably be 30-40A (allowing a safety factor).

it's cheaper if you can use lower voltage such as 230 instead of 480V.
for example AutomationDirect sells GS series drive such as

GS1-22P0 which is $169:
GS1 2.0 HP AC Drive, 230V 3Phase In / 3Phase Out

or
GS2-22P0 which is $266 but powerd from single phase
(still 3 phase output...)


www.automationdirect.com

I've found simlar pricing from other companies as well but the above mentioned $169 seam to be least expencive. it's hard to compete against such prices...

you can also always use mechanical solution (belts or gears0
to lower the motor speed...

panic mode said:

it's cheaper if you can use lower voltage such as 230 instead of 480V.

Click to expand...

440V is three phase, where each phase is 230V. The 440V is the voltage between phases.

Phasor said:

Styx said:

not much to ask...
I have said that the output torque ~15Nm, Torque = i*kt Without any infomation about the torque constant of the machine the current handling of the IGBT's cannot be stated. If the toruqe constant is low the you could need 1000A, but it if is high you could need 10A

Click to expand...

1000A :shock: unlikely - normal sort of figures for torque constant of this size motor seems to be about 1.0 Nm/A (give or take a bit). Thus the current rating of the IGBTs should probably be 30-40A (allowing a safety factor).

Click to expand...

Why is it unlikely!!!

As I stated no infomation on the machine was provided!!!!
Machines I am dealing with are 0.2 Nm/A but they are 20kW machines.

Yes practically the kt will be alot higher for such a low-power machine BUT MY POINT WAS HE WAS ASKING FOR RATING AN IGBT WITH NO INFOMATION!!!!!! and the relevant infomation was the Kt of the machine to spec the machine phase current.

Nigel Goodwin said:

panic mode said:

it's cheaper if you can use lower voltage such as 230 instead of 480V.

Click to expand...

440V is three phase, where each phase is 230V. The 440V is the voltage between phases.

Click to expand...

...sure... in England... (and maybe India as well, i don't know...)
I know that most of the Europe use 380/220 or nowdays 400/230 (3P/1P)
but this wasn't my point (maybe i simply look at things from somewhat
different angle):

unlike Europe, different voltages are quite common in this part
of world (208, 230, 460, 575 and few other odd ones in between
depending on neighbourhood, age, application of who knows what else.
residential power is using single phase "center tap" so you get either
120 per phase or 240 between "phases").

step down transformer might be cheap solution when compared
to price difference of 230 and 460V VFDs (or 600V units).

maybe similar diversity exists in garg29's country because he
had number of posts regarding motor speed control and some
of his posts ware for mentioning lower voltage.

maybe he is working on machine that will be shipped to another
country (this is also very common with our products).

personally i think that suggestion for lower priced option is
a valuable and interesting information regardless if he is buying or
building his own VFD.